Caldicoprobacter algeriensis sp. nov. a New Thermophilic Anaerobic, Xylanolytic Bacterium Isolated from an Algerian Hot Spring (original) (raw)
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International Journal of Systematic and Evolutionary Microbiology, 2012
An anaerobic, moderately thermophilic, terminal-spore-forming bacterium, designated strain USBA AT, was isolated from a terrestrial hot spring located at an altitude of 2683 m in the Andean region of Colombia (04° 50′ 14.0″ N 75° 32′ 53.4″ W). Cells of strain USBA AT were Gram-stain-positive, straight to slightly curved rods (0.9×2.5 µm), that were arranged singly or in pairs, and were motile by means of flagella. Growth occurred at 37–55 °C and pH 6.0–8.0, with a doubling time of 2 h under the optimal conditions (50 °C and pH 7.0). Glucose fermentation in strain USBA AT required yeast extract or peptone (each at 0.2 %, w/v). The novel strain fermented sugars, amino acids, Casamino acids, propanol, propionate, starch and dextrin, but no growth was observed on galactose, lactose, xylose, histidine, serine, threonine, benzoate, butyrate, lactate, pyruvate, succinate, methanol, ethanol, glycerol, casein, gelatin or xylan. The end products of glucose fermentation were formate, acetate, ...
A novel moderately thermophilic, anaerobic, ethanol-producing bacterial strain, 45BT, was isolated from a mixed sediment water sample collected from a hot spring at Potosi, Bolivia. The cells were straight to slightly curved rods approximately 2.5 mm long and 0.5 mm wide. The strain was Gram- stain-variable, spore-forming and monotrichously flagellated. Growth of the strain was observed at 45–65 6C and pH 5.5–8.0, with optima of 60 6C and pH 6.5. The substrates utilized by strain 45BT were xylose, cellobiose, glucose, arabinose, sucrose, lactose, maltose, fructose, galactose, mannose, glycerol, xylan, carboxymethylcellulose and yeast extract. The main fermentation product from xylose and cellobiose was ethanol (0.70 and 0.45 g ethanol per gram of consumed sugar, respectively). Acetate, lactate, propionate, carbon dioxide and hydrogen were also produced in minor quantities. 1,3-Propanediol was produced when glycerol-containing medium was supplemented with yeast extract. The major cellular fatty acids were anteiso-C15 : 0, C16 : 0, iso-C16 : 0, C15 : 1, iso-C14 : 0, C13 : 0 and C14 : 0. The polar lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminoglycolipid and 15 other unidentified lipids were predominant. The DNA G+C content of strain 45BT was 32.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain 45BT is located within the Gram-type positive Bacillus–Clostridium branch of the phylogenetic tree. On the basis of morphological and physiological properties and phylogenetic analysis, strain 45BT represents a novel species, for which the name Caloramator boliviensis sp. nov. is proposed; the type strain is 45BT (5DSM 22065T5CCUG 57396T)
Frontiers in Microbiology
The order Thermoanaerobacterales currently consists of fermentative anaerobic bacteria, including the genus Caldicellulosiruptor. Caldicellulosiruptor are represented by thirteen species; all, but one, have closed genome sequences. Interest in these extreme thermophiles has been motivated not only by their high optimal growth temperatures (≥70°C), but also by their ability to hydrolyze polysaccharides including, for some species, both xylan and microcrystalline cellulose. Caldicellulosiruptor species have been isolated from geographically diverse thermal terrestrial environments located in New Zealand, China, Russia, Iceland and North America. Evidence of their presence in other terrestrial locations is apparent from metagenomic signatures, including volcanic ash in permafrost. Here, phylogeny and taxonomy of the genus Caldicellulosiruptor was re-examined in light of new genome sequences. Based on genome analysis of 15 strains, a new order, Caldicellulosiruptorales, is proposed cont...